Composition wall board and method of making the same



H. E. BROOKBY.

COMPOSITION WALL BOARD AND METHOD OF MAKING THE SAME.

APPLICA ION FILE'J NOV 12, I921.

Patented Sept. 12, 1922.

ATTORNEYS.

Patented Sept. 12, 1922.

HARRY E. BROOKBY, 0F EVANSTON, ILLINOIS, ASSIGNOR T0 UNITED STATES GYP-SUM COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

QOMPOSITION WALL BOARD AND METHOD OF MAKING THE SAME.

Application filed it'ovember 12, 1921. Serial No. 51%,731.

To all whom it may concern:

Be it known that I, HARRY E. BnooKBY, a citizen of the United States,residing at Evanston, in the county of Cook and State of Illinois, haveinvented new and useful Improvements in Composition Wall Board andMethods of Making the Same, of which the following is a specification.

This invention relates to improvements in composition wallboard and themethod of makin the same. 1

l/Val board has been made from calcined gypsum, or a mixture of calcinedgypsum and sawdust, encased between covers of paper and made insuch aform that it may be attached to the studding of a building and be readyfor papering or painting without the necessity of first giving it a coatof plaster.

It is an object of this invention to produce a wallboard of the samecharacteristics, having the same use as the calcined gypsum orcomposition wallboard above described, and the additional advantage ofbeing of considerably less weight,

Plaster wallboard, as now made, using calcined gypsum and sawdust, orsimilar organic aggregates, weighs between 1750 to 2000 pounds, when3/8" thick, per thou sand square feet. At present it is customary tolighten the weight of said board by in .corporating with the gypsumfiller-a sawdust'addition, usually from five to ten per cent by weight,and it is an object of this invention to further lighten the board byreplacing a part of the gypsum itself with some suitable light weight,fireproof mineral.

I have discovered that diatomaceous earth may be advantageously employedfor this purpose. Powdered calcine gypsum, in its dry state, loose,weighs between sixty and seventy pounds per cubic foot, whilediatomaceous earth in the same state weighs between six and twelvepounds per cubic foot. Diatoinaceous earth is a natural product known tothe chemical industy as kieselguhr, guhr, infusorial earth, siliceousearth, diatomaceous earth, fossil flour, tripolite, tripoli and also bythe commercial trade name of celite. It is a soft, white, earthy rock,or conglomerant composed of siliceous skeletons of small aquatic plants,known as diatoms, consisting mainly of silica and silicates in varyingproportions, and is capable of taking and holding four times its weightof water.

'Diatomaceous earth fulfills the requirements of such a mineral, exceptthat mixtures of it and gypsum in the plastic state do not adhere to thepaper forming the outer coverings of such wallboards when p the boardsare dried. Tnthe trade this effect is known as peeling and the boardsare ing the inner core, is placed between these.

two gypsum-coated covering papers. Consequently, the paper does notpeel, for the dried finished board still furnishes gypsum paper contactonly. Thus by givlng the mineral core the proper composition of gypsumand diatomaceous earth, almost any variation in the weight of the boardcan be secured, and still the covering material can be just as firmlyattached to the board as ordinary wallboard.

In a finished wallboard, 3/8 thick, the

two paper covers would represent 2/32", the gypsum coating to each one1/32 ('1/16 on each cover) and the inner core of diatomaceous earthmixture would be 6/32" or 1/2 the thickness of the board. If thediatomaceous earth mixture used as the core weighs 10 pounds per cubicfoot which is 1/6 the weight of gypsum, and the wallboard has half ofits volume made up of the core there this wallboard would weighapproximately one-half the; weight of a gypsum wallboard plus the weightof the diatomaceous earth mixture core, or 1000 pounds plus 167 poundsmaking a total of 1167 pounds per thousand square feet of the improvedboard, 3/8" thick.

known as peelers, that is, where the cover- L material is notparticularly well at 25 proved wallboard, with parts broken away,

The composition of the core may be diatomaceous earth alone, a mixtureof the earth with calcined gypsum, a mixture of the earth with calcinedgypsum and 531W? dust, or a mixture of the earth with an adhesive togive it rigidity when dry, in proportion to the weight desired.

While the preferred form of article preferred form' of core, and asuitable and pref erred means for manufacture are illustrated onwtheattached sheet of drawing, it is to be understood that detail changes,such as the thickness of the core or bonding layers or the proportionsof the core mixture, or different method of distributing the plasticmaterials onto the bed; may be made without departing from the scope ofthis invention.

In the drawings:

Figure l is a View ofside elevation, with parts broken away, of a formof machinery that may be used in the fabrication of the compositionwallboard in accordance with this invention Figure 2 is a view insection of this imillustrating the composition and the foldedlongitudinal edges.

The machine illustrated is of the usual general construction asheretofore used in the manufacture of plaster wallboard. and

comprises a base 1 with spaced apart sup-' ports 2 supporting, rolls ofpaper 3 of the proper width and character for the cover sheets 4: and 5of the wallboard. An. endless belt 6 passes over rollers on the basewhich supports the bottom cover sheet 4 between the supports 2 and theencased board after it leaves the forming mechanism 7 The formingmechanism comprises means for turning over the edges of the lower coversheet 4 to enclose the edges of the wallboard before the feeding of theupper cover sheet 5 thereover, all of which construction is Well knownin this art.

Conveyors 7 and 8 ge provided adjacent each paper roll; support 2 with athird conveyor 9 interposed between them. These conveyors are all of thesame general construction and used in conveying a plastic mixture ofcalcined gypsum, sawdust and Water and depositing the plastic mass uponthe bottom cover sheet in the fabrication of distances apart to allowsufiicient set of the plastic bottom layer on the under cover sheet, ofthe core mixture and of the plastic upper layer thereon and allow of thespreading of each, preferably by spreading rolls 12, wltheatintermingling the ingredients before the lease? application ofthe uppercover sheet. The

remainder of the machine is preferably of a the usual construction.

It is therefore seen that by this method a composition wallboard isformed which comprises a core 11 lighter in weight than calcined gypsumhaving a layer 10 on each material therebetween and-bonded thereto.

3. A composition wallboard comprising cover sheets with layers ofcalcined gypsum bonded thereto and a core of a diatomaceous earthmixture therebetween.

4:. A' composition wallboard comprising a core of bonded diatomaceousearth with a thin layer of calcined gypsum on each side bonded theretoand cover sheets bonded to the gypsumlayers.

5. The method of fabricating composition the provision of a wallboardcomprisin cover sheet, the depositing thereon of'a layer of plasticcementitious material ada ted to bond thereto, the depositing on suclayer of a core of lighter plastic material adapted to bond with saidlayer, the depositing upon the core of a layer of the same material asthe first and the laying of a second cover sheet over said last layer.

6. The method of fabricating composition wallboard comprisin theprovision of a cover sheet, the depositing thereon of a layer of plasticcalcined gypsum thereon, the depositing on such layer of a core oflighter plastic material adapted to bondthereto, the

depositing upon the core of a layer of plas-f tic calcined gypsum andthe laying of a second cover sheet'over said last layer.

' 7. The method of fabricating composition wallboard comprisingtheprovision of a coyer sheet, the depositing of a layer of plasticcalcined gypsum thereon the depositing on such layer of a core ofplastic diatomaceous earth mixture, the depositing upon the 1 core of alayer of plastic calcined gypsum imd the laying of a cover sheet uponsaid last ayer.

8. The method of fabricating compbsition wallboard comprising theprovision of a cover sheet, the forming'of a thin layer ofplastic'calcined gypsum thereon, the forming of a core of plastic bondeddiatomalayer of plastic calcined gypsum upon the said core and theprovision of a sheet upon the lastlayer.

HARRY E. BROOKBY.

ceous earth thereon, the forming of a thin

